Color distortion based on export resolution, not color space
Posted: Thu Dec 31, 2020 12:55 amHere's a weird one: there's a significant color shift in anything I export from Resolve (17b6) at a horizontal resolution of 720 or less and a vertical resolution of 576 or less. Video exported below that resolution gets the color shift I associate with Rec.601 footage being incorrectly interpreted as Rec.709- yellower and more saturated.
This happens for me regardless of:
- source file color space and resolution
- settings within Resolve for input, timeline, or output color space, or color management
- export format (tested ProRes and h264) and settings besides resolution
- timeline resolution (as opposed to the resolution being exported)
- which of my couple computers I'm on (both recent-ish macs running OS X 10.15.7)
- what I use to view the resulting files (which according ffprobe to have identical color_space, color_transfer, and color_primaries between problem and not-problem)
To reproduce (use a source file with chip chart and/or skin tones so it's easy to see)
1 create a new project (resolution, color space, etc don't matter), and import the source video
2 create a new timeline from that source, using project settings
3 in project settings, under Image Scaling set 'mismatched resolution files' to 'center crop with no resizing' (for ease of comparing files)
4 in project settings, under Master Settings set the timeline resolution to custom, 720x577 (make sure the pixel aspect ratio is square, also for ease of comparison)
5 go to Deliver, export in your format of choice
6 under project settings switch the timeline resolution to 720x575 instead of 720x777 (the problem happens at 576 and below, but using 575 avoids pixel aspect ratio complexity)
7 go to Deliver, export in your format of choice
Now compare the two exports.
The same thing happens if you just change the export resolution on the deliver page rather than changing the timeline resolution. If you do this recursively (importing a file with the shift then exporting it again), the colors shift further in the same way each time.
Is anybody else seeing this?
This happens for me regardless of:
- source file color space and resolution
- settings within Resolve for input, timeline, or output color space, or color management
- export format (tested ProRes and h264) and settings besides resolution
- timeline resolution (as opposed to the resolution being exported)
- which of my couple computers I'm on (both recent-ish macs running OS X 10.15.7)
- what I use to view the resulting files (which according ffprobe to have identical color_space, color_transfer, and color_primaries between problem and not-problem)
To reproduce (use a source file with chip chart and/or skin tones so it's easy to see)
1 create a new project (resolution, color space, etc don't matter), and import the source video
2 create a new timeline from that source, using project settings
3 in project settings, under Image Scaling set 'mismatched resolution files' to 'center crop with no resizing' (for ease of comparing files)
4 in project settings, under Master Settings set the timeline resolution to custom, 720x577 (make sure the pixel aspect ratio is square, also for ease of comparison)
5 go to Deliver, export in your format of choice
6 under project settings switch the timeline resolution to 720x575 instead of 720x777 (the problem happens at 576 and below, but using 575 avoids pixel aspect ratio complexity)
7 go to Deliver, export in your format of choice
Now compare the two exports.
The same thing happens if you just change the export resolution on the deliver page rather than changing the timeline resolution. If you do this recursively (importing a file with the shift then exporting it again), the colors shift further in the same way each time. Is anybody else seeing this?